Old vs New part one

Over the years, I have moved through a few different views regarding the applicability of the law of God, in the life of the Christian.  As a youth, I grew up with old testament law not even being considered.  As I became a Calvinist,  a variety of views were considered and worked through, with my landing in the theonomic camp,  via the teaching of Dr. Greg Bahnsen. Now, having come into Orthodoxy, oddly enough,  I have come to a much more covenantal position.
The main point underlying covenant theology is recognizing the covenant changing work of Jesus Christ. Jesus' life, death and resurrection fulfilled everything of the old covenant and establish the new.  But, for some reason, adherents of covenant theology seem to want to hold onto much of the legal aspects of the old covenant. But why?
I understand, historically, the church had held that all of the old covenant had been fulfilled and faded away, as we see in Hebrews 8:13. And this makes perfect sense.  In the time prior to the incarnation,  all interaction between God and man was temporal and physical.  When man was obedient, he received physical blessings,  long life, peace in the land, health, wealth and many children.  When man was disobedient, the opposite occurred,  short life, war, disease and barrenness. Even the manner of life was dictated in physical terms, a law written on stone. And it had to be this way, for death had possession of man and control over him.  Man could not look forward to an eternity in heaven.  Heaven wad closed to him.
But now, Jesus' work had destroyed the power of death, so the entire structure has been changed.  We no longer have a physical temple, physical blessings or curses and no longer a law written on stone. Now we have the Holy Spirit, leading us, filling us and working on our hearts. We are no longer directed by law but by love. Our motivation is no longer that of obedience in order to avoid curse, but a response of love for the redemptive work already done by Jesus.  We don't seek after holiness in order to gain eternal life, we seek a life of holiness because we have already been saved and now we can form our souls to actually be like Christ, the form we were made to be.